1. Joost Dekker PhD Department of Psychiatry & Department of Rehabilitation Medicine VU University Medical Center, Amsterdam, Netherlands Knikkende knieën Over instabiliteit en loopvaardigheid bij artrose van de knie 1

2. Osteoarthritis Prevalence symptomatic OA in among adults aged ≥45 years –Knee 16.7% –Hip 9.2% Top 10 of most disabling diseases in European region Most important cause of pain and disability in the elderly Jordan et al, 2007 WHO, 2008 Conaghan et al, 2008

3. Impairments of cartilage and bone –Findings on X-rays, MRI Physical impairments –Muscle weakness, instability Sensory impairments –Pain, stiffness, instability Activity limitations –Walking, rising Problems in participation –Work Osteoarthritis – multiple levels 3

4. Impairments of cartilage and bone –Findings on X-rays, MRI Physical impairments –Muscle weakness, instability Sensory impairments –Pain, stiffness, instability Activity limitations –Walking, rising Problems in participation –Work Osteoarthritis – multiple levels 4

5. Instability Sudden loss of postural support across the knee at a time a weight bearing Self report –Sensation of buckling, shifting, or giving way of the knee –Sensory impairment Observed measure –To be developed –Physical impairment 5 Felson et al, 2007

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7. Instability In knee OA – 60 – 80 % Instability is associated with activity limitations –Walking speed, self reported walking limitations 7 Fitzgerald et al, 2004 Schmitt et al, 2008 van der Esch et al, 2012 Knoop et al, 2012 Nguyen et al, 2014

8. Instability In knee OA – 60 – 80 % Instability is associated with activity limitations … and with falls 8 Fitzgerald et al, 2004 Schmitt et al, 2008 van der Esch et al, 2012 Knoop et al, 2012 Nguyen et al, 2014

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10. Instability Reduced muscle strength is associated with instability Quadriceps and hamstring muscles are stabilizers of the knee 10 Knoop et al, 2012

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12. van der Esch et al, 2006 Proprioception - perception of position and movement 12

13. Muscle strength, proprioception and activity limitations van der Esch et al, 2007 Replication Holla et al, 2012 13

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15. Pain 15 Felson et al, 2007

16. Arthrogenic muscle inhibition 16 Stokes and Young, 1984

17. Tactile stimulation Lack (-/-) tactile stimulation –Instability ? 17

18. Arthrogenic muscle inhibition 18 Rice and McNair, 2010

19. Tactile stimulation Lack tactile stimulation (-/-) –Instability ? Additional tactile stimulation (+/+) –Soft brace 19

20. Additional tactile stimulation 20 Pegoretti et al, 2015

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22. Instability in knee OA Highly prevalent –60 – 80 % Activity limitations (walking), falls Muscle strength Proprioception Pain Tactile stimulation 22

23. Instability in knee OA Highly prevalent –60 – 80 % Activity limitations (walking), falls Muscle strength Proprioception Pain Tactile stimulation 23 Exercise therapy Soft brace

24. Further information j.dekker@vumc.nl 24

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